Suspended overpass

ABSTRACT

An overpass structure has three transverse arches which are ground supported, and two longitudinal arches which are suspended, as by hanger cables, from the transverse arches. The roadway is suspended from the transverse and longitudinal arches, in alignment with and between the longitudinal arches. Horizontal struts provide horizontal support.

United States Patent Pleasants 5] Apr. 11, 1972 [54] SUSPENDED OVERPASS Engineering News Record, Feb. 25, 1954, page 46 [72] Inventor: 3222: 53 23 Box Primary Examiner-Jacob L. Nackenoff Attorney-Paul & Paul [22] Filed: Jan. 4, 1971 21 Appl. No.: 103,748 [57] ABSTRACT An overpass structure has three transverse arches which are [52] U Cl. i 14/] 14/19 14/24 ground supported, and two longitudinal arches which are 51 hit. c|...'.'.'.'.'.'.'.IIIIIIIIIY'" .......Eo1'd 1/00 suspended as by hanger cables, from transverse arches 58 Field of Search ..14/1 24-26 18 The roadway is Suspended from the transverse and longitu- 14/19, 2 dinal arches, in alignment with and between the longitudinal arches. Horizontal struts provide horizontal support.

[56] References Cited OTHER PUBLICATIONS 3 Claims, 4 Drawing Figures Engineering News-Record, Nov. 16, 1950, page 26 PATENTEDAPR 11 I972 3,654, 652

SHEET 1 OF 2 INVENTOR. WILLIAM W. PLEASANTS BY Mv M AT TORN EYS.

PATENTEDAPR 11 I972 3. 654, 652

SHEET 2 OF 2 INVEN'I'OR.

Fig. 4 WILLIAM w. PLEASANTS ATTORNEYS.

SUSPENDED OVERPASS CROSS-REFERENCE TO RELATED APPLICATION The invention described and claimed in the present application represents an improvement over that shown and described in my U.S. Pat. No. 3,359,587, granted Dec. 26, 1967, entitled Suspended Overpass.

BACKGROUND OF THE INVENTION The present invention relates to overpasses for facilitating the movement of vehicular or pedestrian traffic at the intersection of two crossing thoroughfares.

DESCRIPTION OF THE PRIOR ART In my U.S. Pat. No. 3,359,587, I describe and claim an overpass structure for facilitating the movement of vehicles or pedestrians at intersecting thoroughfares. The structure shown in the patent comprises a rigid framework which includes a pair of transverse rigid arch members fully spanning the minor thoroughfare on opposite sides of the major thoroughfare. Opposite ends of the arch members are supported upon and anchored to the ground outside the roadways of the thoroughfares. A third rigid arch member runs in the longitudinal direction of the minor thoroughfare and fully spans the major thoroughfare, with opposite ends thereof supported upon and anchored to the ground in the roadway between the lanes of traffic of the minor thoroughfares. A system of auxiliary frame members innerconnects the several arch members for mutually bracing the framework against lateral movement. An overpass roadway, aligned with the minor thoroughfare, with lanes on both sides of the longitudinal arch, is freely suspended from the framework above the intersection of the two thoroughfares, and roadway ramps are provided to the lanes of the overpass roadway from the minor thoroughfare.

As indicated above, the framework of the overpass structure shown in my U.S. Pat. No. 3,359,587, includes a longitudinal arch located between the lanes of the overpass, with opposite ends of the longitudinal arch extending down to or into the ground in the roadway of the minor thoroughfare.

SUMMARY OF THE INVENTION A primary purpose of the present invention is to provide a suspended overpass structure of the general type shown in my U.S. Pat. No. 3,359,587, but which is so designed that it does not have a longitudinal arch located in the middle of the minor thoroughfare, since such an arch forces the overpass to have two separate lanes in order to avoid an obstruction in the overpass roadway.

The foregoing purpose is accomplished, in accordance with the present invention, by the provision of a pair of longitudinal arches, one on either side of the overpass roadway and parallel therewith. The longitudinal arches are suspended, as by hanger cables, from the transverse arches. Neither of the two longitudinal arches extends below the elevated overpass, thereby avoiding obstructions which would otherwise be placed in the path of traffic on the minor thoroughfare below the overpass. The overpass roadway is suspended, as by hanger cables, from the transverse and longitudinal arched members. The overpass roadway is braced, as by struts or stringers against lateral forces.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective illustration of a suspended overpass structure in accordance with the present invention;

FIG. 2 is an elevational view from the major thoroughfare;

FIG. 3 is an elevational view from the minor thoroughfare;

FIG. 4 is a plan view.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to FIGS. 1-4, the roadway is a standard two-lane roadway with no median. The roadway may be assumed to conform in all respects and dimensions to the U.S. Bureau of Public Roads standard designs.

The roadway 10 is suspended from three transverse arches 21, 22 and 23 each of which spans the minor thoroughfare 12 and has its foundations on the ground or street level outside of the curbs, thus providing good visibility for motorists at ground level.

Cables 31 which hang from an end transverse arch 21 support one end of a pair of longitudinal arches 41 and 42. The other ends of longitudinal arches 41 and 42 are supported by cables 35 which hang from end transverse arch 23. The centers of the longitudinal arches 41 and 42 are rigidly connected to the underside of the center transverse arch 22. This supplies lateral support to the center transverse arch.

The roadway 10 is suspended from the three transverse arches 21, 22, 23 and from the two longitudinal arches 41, 42, by cables which hang from the arches. There are five pairs of cables 31, 32, 33, 34 and 35, one cable of each pair on each side of the roadway, atotal of ten suspension cables. Three of the pairs of cables, 31, 33 and 35, are suspended from the three transverse arches 21, 22, and 23. The other two pairs of cables, 32 and 34, are suspended from the longitudinal arches 41 and 42. Thus, the longitudinal arches support, through the suspension cables 32 and 34, the sections of roadway between the transverse arches.

Horizontal support for the two end transverse arches 21 and 23 is provided by two pairs of horizontal struts 51 and 53 which run in the same vertical planes as the longitudinal arches 41 and 42, and directly above the end portions of the longitudinal arches. The pairs of struts 51 and 53 extend from the end transverse arches 21 and 23 to the longitudinal arches 41 and 42.

Horizontal support for the roadway 10 is provided by three pairs of horizontal struts 61, 62 and 63 which extend laterally from the roadway out to the transverse arches 21, 22 and 23.

Horizontal bracing members 71 and 72, running transverse relative to the roadway 10, extend between the longitudinal arches 41 and 42 and tie them together midway between the transverse arches.

The system of longitudinal arches and struts shown and described form a truss at each side of the overpass roadway which provides lateral support to the transverse arches.

The suspended overpass roadway is rigidly fixed at both ends by ramps of conventional design.

The transverse and longitudinal arches may, if desired, be formed of reinforced concrete precast on the site, and raised into position, as by cranes. A typical suspension structure may, for example, have the following dimensions: The transverse arches may be reinforced concrete 2 feet wide and 4 feet high in section, on a diameter of feet. The longitudinal arches may be 1 foot wide and 2 feet high in section, on a 72- foot radius.

While the mid-transverse arch 22 is highly desirable, it may be omitted in some installations. If omitted, the end transverse arches 21 and 23 would have to be heavier. The weight of the overpass roadway is borne by the transverse arches. The roadway overpass and the longitudinal arches are suspended, as by cables from the transverse arches. The horizontal stringers or struts provide lateral stability.

Ramps 11 are, of course, provided to connect the suspended overpass roadway 10 with the'minor thoroughfare. The ramp slope may be between 5 and 8 percent. The length of the overpass roadway may be 1 12 feet (in four 28-foot sections). With an 8 percent ramp slope, each ramp may be 200 feet long, giving the structure an overall length of 512 feet. The vertical clearance may be 16 feet. The overall height of the structure may be 46 feet. The roadway bridge structure 10 may have a thickness of 18 inches, with floor beams 14 X 12 inch, stringers 24 X 12 inch, and concrete thickness 5 inches, and thickness of pavement above floor beams 2 inches. The bridge parapet 15 may be 12 inches wide and 18 inches high and the curb may be 12 inches wide and 10 inches high. The bridge structure is seen in cross section in FIG. 3. As there shown, and as previously indicated, the longitudinal arches 41 and 42 are in the vertical planes of the parapets 15.

Features of the structure described and claimed herein, and advantages thereof, includes the following:

Increases intersection capacity by 80 percent with increased safety.

Two straight-through lanes of minor street are carried over six lanes of major street.

Right and left turns to and from major street continue at ground level.

No acquisition of property is necessary.

No excavation or obstruction of major street traffic.

Contained with l-foot right of way on minor street and 120 foot on major.

Suspension of longitudinal arches above ground eliminates obstruction (pier) in roadway of minor street.

Increases maneuvering area at entrance to intersection with 14-foot clearance.

Reduces bridge thickness, ramp length, overall length and overall cost.

What is claimed is:

1. A suspended overpass structure comprising:

a. three transverse arches, there being one transverse middle arch and two transverse end arches, supported at their ends on the ground;

b. two longitudinal arches;

c. suspension means depending from the transverse arches and connected to and supporting the longitudinal arches at the ends thereof;

d. a roadway supported between said longitudinal arches and parallel therewith at the level of ends of said longitudinal arches;

e. suspension means depending from the longitudinal arches and connected to the sides of said roadway and providing suspension support for said roadway;

. horizontal strut members between the sides of said roadway and said transverse arches and providing lateral support for said roadway;

g. means rigidly connecting the centers of the longitudinal arches to the middle transverse arch.

2. A suspended overpass structure according to claim 1 characterized in that strut means are provided in the vertical plane of said longitudinal arches and above the end portions thereof connecting said longitudinal arches to said end transverse arches.

3. A suspended overpass structure according to claim 2 characterized in that horizontal bracing means are provided between said longitudinal arches about midway between said transverse arches. 

1. A suspended overpass structure comprising: a. three transverse arches, there being one transverse middle arch and two transverse end arches, supported at their ends on the ground; b. two longitudinal arches; c. suspension means depending from the transverse arches and connected to and supporting the longitudinal arches at the ends thereof; d. a roadway supported between said longitudinal arches and parallel therewith at the level of ends of said longitudinal arches; e. suspension means depending from the longitudinal arches and connected to the sides of said roadway and providing suspension support for said roadway; f. horizontal strut members between the sides of said roadway and said transverse arches and providing lateral support for said roadway; g. means rigidly connecting the centers of the longitudinal arches to the middle transverse arch.
 2. A suspended overpass structure according to claim 1 characterized in that strut means are provided in the vertical plane of said longitudinal arches and above the end portions thereof connecting said longitudinal arches to said end transverse arches.
 3. A suspended overpass structure according to claim 2 characterized in that horizontal bracing means are provided between said longitudinal arches about midway between said transverse arches. 